The present invention relates to universal joints with a shock absorbing material between the yokes and the respective bearings.
Modern vehicles are often equipped with universal joints that comprise a cross member having four shafts or trunions that lie in a same plane. Bearings are mounted on each shaft, and two yokes are mounted on opposed pairs of shafts. The yokes are mounted at positions spaced ninety degrees relative to each other and are connected to drive shafts. This arrangement allows rotation to be transmitted through varying angles between the drive shafts. This type of universal joint is particularly popular in heavy duty vehicles such as trucks.
Universal joints experience a great deal of stress and vibration and are exposed to a hostile environment on the underside of a vehicle. Thus, the connection between the yoke and respective bearings should have the ability to withstand imposed shocks and torsional vibrations. The universal joint designs utilized in the past have not always achieved this goal for yoke and cross member connections.
Typically, universal joints use yokes that have cylindrical bores to receive a bearing cup and shaft. The cylindrical bore surrounds and supports the bearing cup during operation of the universal joint. The yokes and bearing cups are typically formed of rigid metals.
One problem with this arrangement is that the bearings are rigidly aligned and fitted to the cylindrical bores of the yokes. This results in a high degree of shock transmission which, in turn, causes undesirable vibrations to the elements of the universal joint.
It has been proposed to use resilient materials to form the bearings. However, such bearings do not provide adequate support.
It is an object of the present invention to address this problem by providing a conventional universal joint with a system for absorbing shocks imposed during usage. Such a system would significantly reduce undesirable torsional vibrations and ultimately lengthen the life span of the elements of the universal joint.
In a disclosed embodiment of the present invention, a conventional universal joint is provided with a shock absorbing system. This system is designed to dissipated imposed shock on the universal joint, in particular between the yoke and respective bearings. This is accomplished by introducing a shock absorbing elastomeric material between an exterior surface of the universal joint bearing cup and the interior surface of the cylindrical bore of the respective yoke. The shock absorbing elastomeric material may be any of a known suitable substance, such as a polyurethane with acceptable toughness. The shock absorbing elastomeric material acts to xe2x80x9ccushionxe2x80x9d the connective areas between the cylindrical bore of a yoke and the exterior of the respective universal joint bearing cups. The bearing cups and the yoke are both formed of metal and the shock absorbing material is more resilient than the material of the bearing cups and the yoke. Thus, the xe2x80x9ccushioningxe2x80x9d in the connective area serves as a self aligning and load distributing shock absorbing system.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.